In general, battery modules for hybrid vehicles are arranged in rows inside a storage device, in electrical and mechanical communication with each other. A typical storage device has several rows, each with an air inlet at one end and an air outlet at the other end. The rows are separated from one another by walls defining through holes therein. Fins are provided in the spaces defined between the walls, and cool the battery modules with the air flowing through the air inlets. Each fin includes a plate member, blocking plates adjacent to the thorough-holes, and a flange that fastens the fin to the housing.
The structure of the typical device is complicated. Further, some areas are over cooled due to air flowing in gaps between the blocking plates and the walls. Further, the portions of the battery modules in contact with the through-holes are never cooled, because air does not contact with them.